The present invention relates to a device for automatically controlling a track-bound vehicle.
In a known device of this kind, particularly for magnetic levitation railways, the control of the generally driverless vehicle is performed from a stationary operation center, applying a redundantly configured operations management technology. A part thereof particularly is a travel computer which on the basis of prescribed data depending on the track profile controls the vehicle speed and brings the vehicle to a standstill within preselected stopping zones (central railway stations) in accordance with as schedule. Apart thereof, there may be other stopping zones (auxiliary stopping zones) in which the vehicle is stopped only in case of emergencies.
For example, in case of a magnetic levitation vehicle, long-stator motors serve for driving and comprise a long-stator extending along the guideway and being provided with grooves. Alternating current windings are laid in these grooves and are fed with a three-phase current of a variable amplitude and frequency in order to generate a travelling wave advancing along the long-stator. The excitation field is generated by carrying magnets arranged in the vehicle which apart from the carrying function, which causes the levitation, also provide the excitation field for the long-stator motor. The frequency of the travelling wave determines the vehicle speed, which is the reason why long-stator motors are apt both for driving and braking the vehicle.
To enable the vehicle to be brought to a standstill even in case of a failure of such a driving and braking system, it is equipped with an additional brake in form of a gripper brake (DE 30 04 705 A1), an eddy-current brake or the like.
To facilitate controlling of the vehicle from the operation center, it is furthermore known (DE 33 03 961 C1) to arrange at least one data carrier in form of a measuring strip or the like along the guideway, said data carrier containing absolute location data. In this case, a data acquisition detection unit is mounted in the vehicle which continually scans the data carrier to derive actual values for the location and speed of the vehicle and to transmit these actual values in the form of status signals, for example in wireless mode, to the operation center.
Stopping of a vehicle at preselected stopping targets of a stopping zone in general is achieved by controlling the speed of the vehicle by the aid of the driving and braking system in accordance with a given braking curve which, for example, is deposited in a control computer of the vehicle. Moreover, means are expediently provided for in the vehicle which may be part of the control computer and which compare the actual values of the vehicle speed obtained by scanning the data carriers with location-dependent limit values and/or permissible maximum speeds that are defined for each location (position) of the guideway and which are preferably also stored in the control computer. If it is determined that the permissible maximum speed has been reached or exceeded, this is regarded as a sign indicative for a defect in the driving and braking system. Consequently, a control signal indicating this fault is generated by the control computer. On the one hand, the control signal is transmitted in wireless mode per radio to the operation center in order to shut-off the driving and braking system, i.e. in case of a magnetic levitation vehicle to shut-off the electrical current flowing through the assigned long-stator winding. On the other hand, the control signal is supplied to the additional brake in order to switch it on and to brake the vehicle despite the defective driving and braking system and to bring it to a standstill at the preselected target stopping point of the stopping zone.
Devices of this kind as well as other possible braking maneuvers for these devices applied in particular on occurrence of various disturbances are widely known (e.g. z. B. DE 38 07 919 C2, DE 39 17 058 C1, ZEVrail Glasers Annalen, Special Edition Transrapid, October 2003, page 70 to 94 in particular).
A hitherto inevitable disadvantage of such control devices is that the transmission of control signals in wireless mode to the operation central is associated with non-negligible times for processing the control signals themselves and for switching-off the drive and brake system to be executed thereupon. The time delays caused thereby during initiation of brake maneuvers may lead to an overriding of preselected target stopping points in the stopping zones. This comes true especially if due to a deficient drive and brake system the vehicle is erroneously accelerated rather than slowed down during the time delays. Because of such operational disturbances which cannot be avoided it is required to provide a so-called connecting (extension) guideway downstream of the target stopping point of each stopping zone to prevent the vehicle from leaving the guideway when riding beyond the preselected target stopping point and from coming to a standstill in an inaccessible guideway section. It is to be considered insofar that a time delay of one second at a traveling speed of 200 km per hour corresponds to a path length of approximately 55 m.
Another operational disturbance may occur when starting the vehicle from a stopping zone due to commencing the starting phase with the wrong traveling direction because of a defect affecting the drive and brake system or the operations management technology. In this case, the time lags during a signal transmission and signal processing performed in wireless mode or the like may involve that a target stopping point in the wrong direction has already been exceeded by far before a command given by the operations management technology for stopping of the starting phase becomes effective.
Corresponding disadvantages in the area of stopping zones may result on existence of other traveling states of the vehicle.